Reinforcement of a sheet metal component in a vehicle bodywork

ABSTRACT

The invention relates to a reinforcement assembly for a sheet metal component in a vehicle bodywork by a second reinforcement piece formed as an extruded light metal section which is additionally secured thereto. The sheet metal component to be reinforced runs straight in a first spatial direction and is curved only in the other two spatial directions. According to the invention, the extruded light metal reinforcement piece is shaped to conformingly fit the curved surfaces of the sheet metal component. The sheet metal component and the reinforcement piece are preferably adhesively secured together. A preferred use of the invention is for reinforcing the sheet metal vehicle floor tub in the high peak stress region of the rear safety belt anchor points. The arrangement of the invention provides an effective reinforcement for heavy loads with good force transmission. The extruded section is preferably formed with a channel sized for receiving a nut portion of a nut and bolt fastener for securing additional components such as a safety belt anchor point, an automatic winding device, a tank support or the like.

FIELD

The invention relates to structural reinforcement of sheet metalcomponents in a vehicle bodywork, and more particularly to areinforcement assembly for the vehicle floor pan in regions of thesafety belt anchor points.

BACKGROUND

In the typical motor vehicle bodywork constructed from sheet metalcomponents, it is often necessary to reinforce the sheet metalcomponents in regions where heavy strain occurs. It is therefore commonpractice to employ a so-called "sheet doubling" technique whereby one ormore additional metal sheets are welded onto the bodywork at the heavystrain regions. Also, the surrounding sheets are usually provided withcrimps for reinforcement.

The connection of the rear safety belt anchor assembly to the vehiclefloor pan is an example region in the sheet metal vehicle bodywork wherelarge peak stresses are known to occur under load. The safety beltanchor points lie roughly in the region where the floor pan adjoins therear longitudinal bearer member and curves upward to meet the rear seatbulkhead. In the usual practice, the above-described sheet doublingtechnique is employed to provide the necessary reinforcement of thesingle sheet floor pan at the safety belt anchor points. Additionally,the added metal sheet may include a nut cage or nut welded thereto foruse in securing the anchor mechanism of the safety belt or automaticseat belt winding device. In addition to the sheet doubling, thesurrounding sheets must also be crimped for further reinforcement.

The fabrication of the reinforced safety belt anchor points as describedabove is costly since a large number of sheet metal components arerequired which, in turn, requires a large number of welding and crimpingsteps. Aside from the localized reinforcement for the belt anchor, noother significant improvement is achieved with regard to the rigidity orvibrational behavior of the bodywork itself in the reinforced region.Further, the additional fastening of other parts of the vehicle to theadded metal sheet is not possible without further modification andadditional expense.

From Japanese patent document JP-A-58 136 572 there is disclosed areinforcement arrangement for a hollow section rear pillar of a vehiclebodywork constructed of two drawn metal sheets which are weldedtogether. The rear pillar forms a portion of the vehicle frame boundaryopening for a hatch back door and is reinforced along one interior wallportion by an additional structural piece in the region where themounting structure for the gas cylinder door opening/closing mechanismconnects to the rear pillar. The reinforcing piece is shaped tocorrespond to the two adjacent inner walls of the hollow section rearpillar and is positively locked against these inner walls over a lengththereof. A single set of screw fasteners connect both the internalreinforcing piece to the inner walls of the hollow section and the gascylinder mounting structure to the outer walls of the hollow section. Asdisclosed, this is a very specific plate doubling embodiment forstiffening a hollow section bearer member as mentioned at the outset.This document does not teach or suggest a reinforcement assembly for afloor tub in the high strain region of the rear safety belt anchorpoints.

Reinforcing plates and reinforcing inserts in hollow section bearermembers of a vehicle bodywork are also known from German patentdocuments DE 2 435 768 A and DE 2 412 506 A. The placement of suchreinforcing plates within the hollow section bearer members is difficultand time-consuming, due to the difficult manipulation and crampedconditions in the finished state of the bodywork.

Various solutions for adjustably connecting together sheet metalcomponents in a vehicle bodywork are known in the art. For example,Japanese patent document JP-A-1 197 182 discloses a fender bench formedas an extruded aluminum profile in which an open supporting channel isformed by two opposite claw sections which accommodate a nut plate.Furthermore, from European patent document EP 0 136 264 83 there isdisclosed a known profile rod having an open supporting channel forinsertion of nut plates.

However, there is still a definite need in the art for a simple and lowcost solution for the reinforcement of the vehicle floor pan in the highregion of the seat belt anchor point and wherein the reinforcement alsoincludes means for easy attachment of the seat belt anchor assembly.

THE INVENTION OBJECTS

It is therefore an object of the present invention to provide a low costand simple reinforcement assembly for a metal sheet portion of a vehiclefloor pan in the peak stress regions of the rear safety belt anchorpoints and whereby additional structural pieces such as a safety beltanchor and/or an automatic winding device may be secured thereto.

It is another object of the invention to provide a reinforcementsolution for a vehicle floor tub of the type described which providesadditional stiffness to the surrounding portions of the reinforcedregion of the floor pan and which further improves the vibrationalbehavior of the vehicle bodywork.

It is another object of the present invention to provide a reinforcementsolution for a vehicle pan of the type described which exhibits improvedstrength for resisting deformation in the event of a side collision tothe vehicle body.

Other and further objects, features and advantages will no doubt becomeapparent from the following description, drawings, and appended claims.

DRAWINGS

FIG. 1 is an isometric view illustrating a reinforcement assembly for asheet metal vehicle floor pan in the region of the rear safety beltanchor point constructed in accordance with one embodiment of thepresent invention.

FIG. 2 is a cross-section view taken along the line and in the directionof arrows A--A of FIG. 1.

SUMMARY

In accordance with a preferred embodiment of the present invention, thesheet metal component of the vehicle bodywork being reinforced is theportion of the sheet metal floor pan where the rear safety belt anchorpoints are located. An extruded section, preferably an extruded lightmetal section, is used as a reinforcement piece and is formed as atransverse bearer member for undergirding the floor pan region of thevehicle extending from the side rear longitudinal bearer members toapproximately the middle portion of the floor pan. This arrangementprovides sufficient reinforcement for the rear safety belt points whensubjected to large peak stresses. The peak stresses are reduced under afavorable flow of force in view of the large area of support afforded bythe transverse bearer member to the other surrounding metal sheets. Theextruded section reinforcement piece (transfer bearer member) alsostiffens its entire surroundings which, in turn, improves thevibrational behavior and rigidity of the vehicle body, especially in theevent of a side collision. In cross-section view, the reinforcementpiece has a first generally horizontal plate-like portion disposed flatagainst the bottom generally horizontal rear portion of the vehiclefloor pan and is joined along one rearwardly disposed edge by a secondmiddle plate-like portion which slants upward at an angle such that itconforms to the raised upward rear region of the floor pan which meetsthe rear bulkhead or trunk compartment.

Thus, as a rule, no crimping is necessary in the surrounding sheet metalportions of the floor pan region. Also, the multiple sheet metalcomponents normally used in the complicated sheet doubling procedurealong with the attendant welding chores are no longer needed.

It is advisable to join the extruded section reinforcement piece to thesheet metal component by an adhesive connection in order to avoid thepeak stresses which may arise during welding or riveting. A weldconnection is particularly undesirable since it is well known that thewelding of aluminum results in a loss of strength in the zone of thermalinfluence. This, in turn, would give rise to a connection which is veryvulnerable to cracking in the event of a collision. Such an adhesiveconnection is simple and inexpensive to produce in view of the largesurface areas available to ensure firm adhesion.

Since it is only necessary to reinforce a rather small region of a largesheet metal component by a piece of extruded section, it is proposedthat this reinforcement piece be applied directly to the heavily loadedpoint at the back side of the sheet metal component in the direction ofloading. This arrangement provides effective absorption of a load andstill exhibits a favorable flow of force.

In an advantageous embodiment of the invention, it is proposed toprovide the extruded section reinforcement piece with an additionalangle in the form of a third plate-like portion and a lengthwise channelto facilitate fastening of other components to the floor pan. Forexample, fastening components such as nut plates, seat guides, etc., canbe inserted into the lengthwise channel and can be maintained in adesired position by stamping the sidewalls of the channel. Furthermore,the fastening elements may be slidably positioned along the course ofthe channel to provide additional flexibility and adjustmentpossibilities. Further still, the upstanding walls of the channelprovide added strength and rigidity to the extruded sectionreinforcement piece.

DETAILED DESCRIPTION OF THE BEST MODE

The following detailed description illustrates the invention by way ofexample, not by way of limitation of the principles of the invention.This description will clearly enable one skilled in the art to make anduse the invention, and describes several embodiments, adaptations,variations, alternatives and uses of the invention, including what wepresently believe is the best mode of carrying out the invention.

FIG. 1 represents a partial isometric view of the bottom rear area ofthe bodywork of a vehicle. In this figure there is shown a rearlongitudinal bearer member 4, a rear transverse seat bearer member 5,and a partial section of a floor pan 6 having an upwardly rising piece 7which meets the bulkhead 8 of a trunk area 9.

FIG. 2 is a cross section view of a segment of the reinforcementassembly 1 taken along the line and in the direction of arrows A--A ofFIG. 1. The reinforcement arrangement 1 comprises a sheet metalcomponent 2 and an extruded section reinforcement piece 3. In thisexample, the sheet metal component 2 corresponds to the rear portion ofthe bottom horizontal floor pan region 6 of FIG. 1.

The rear anchor points for a safety belt (not shown) are normallysituated in the region 10 where the rear longitudinal bearer member 4joins the upwardly rising section 7 of the floor pan 6. Due to the largepeak stresses which occur at the safety belt anchor point region 10under loading, it is proposed to reinforce this region by the extrudedsection reinforcement piece 3.

As is best seen in FIG. 2, the extruded section reinforcement piece 3lies flush against the rear and bottom end portions of the sheet metalcomponent 2 (i.e., the rear portion of floor pan 6). The extrudedsection reinforcement piece 3 preferably forms a transverse bearermember extending from the outer side rear longitudinal bearer 4 towardsthe middle portion of the vehicle section underbody.

The extruded section reinforcement piece 3 includes a first generallyhorizontal plate-like portion 11 which extends rearwardly and upwardlyat an angle to form a second middle portion 12 which in turn is angleddownwardly slightly to emerge into a third upwardly disposed plate-likeportion 13. The first generally lower horizontal plate-like section 11conforms to the underside of the sheet metal component 2 or floor pan 6and the middle and upper portions 12 and 13 conform to the upwardlyrising contour 7 of the floor pan in the region of the rear bulkhead 8.The upper third plate-like portion 13 is bent somewhat towards thehorizontal direction. The second middle section 12 includes two cagesections, 14 and 15, which form an open supporting channel 16 whichpreferably extends across the entire width of the second middle portion12 in the transverse direction.

The supporting channel 16 is preferably sized sufficiently large toreceive a nut plate 17 (shown in phantom) for securing the safety beltand/or for receiving a fastening means for other items such as forexample, an automatic seat belt winding device or a tank.

The angled or bent configuration of the extruded section reinforcementpiece 3 in combination with the channel walls 14 and 15 result in areinforcement having great bending rigidity such that the extrudedsection reinforcement piece 3 acts as a transverse bearer member in thevehicle bodywork. In a preferred embodiment a transverse bearer memberextends across the entire width of the vehicle body from side to side asa single piece. However, it is understood it may also be divided at amiddle portion or merged into a central longitudinal bearer member. Suchan transverse bearer member stiffens the surrounding portions of thevehicle bodywork, especially when provided with additional upstandingchannel walls 14 and 15 and also improves the rigidity and vibrationalbehavior of the bodywork.

The flat plate-like portions 11, 12, 13 of the extruded sectionreinforcement piece 3 also provides a sufficiently large contact surfacearea such that peak stresses which occur under loading are reduced witha favorable flow of force. The large surface area also permits theconvenient use of adhesives to positively secure the extruded sectionreinforcement piece 3 to the sheet metal component 2 (i.e., vehiclefloor pan 6). Furthermore, the use of extruded light metal for thereinforcement piece 3 provides an extra measure of corrosion resistanceto the underbody of the sheet metal bodywork. The cage sections 14 and15 for the supporting channel 16 provide an easy means for fasteningelements such as safety belt anchor points, tank supports, seat holders,and the like.

It should be understood that various modifications within the scope ofthis invention can be made by one of ordinary skill in the art withoutdeparting from the spirit thereof. We therefore wish our invention to bedefined by the scope of the appended claims as broadly as the prior artwill permit, and in view of the specification if need be.

We claim:
 1. A reinforcement assembly for a sheet metal vehicle floor pan comprising in operative combination:a) a light metal extruded section reinforcement member configured to transversely undergird and be matingly secured to a rearwardly disposed portion of a vehicle floor pan in a region of at least one safety belt anchor point including:i) a first substantially horizontal plate-like portion configured to matingly engage a substantially flat bottom surface portion of said vehicle floor pan, said horizontal plate-like portion having at least one rearward edge; and ii) a second upwardly angled plate-like portion connected along said rearward edge of said first plate-like portion and configured to matingly engage an upwardly raised portion of said floor pan in a region where said floor pan adjoins a rear bulkhead, said second plate-like portion having at least one upper rearward edge, said second plate-like portion includes a channel, C-shaped in cross section, formed along an outward facing wall thereof, said channel having a pair of spaced apart upstanding side walls with laterally inwardly extending ends, said walls and ends defining cage sections for retaining fastening elements of other components for attachment to said floor pan.
 2. A reinforcement assembly for a vehicle floor pan as in claim 1 wherein said channel has a width dimension substantially equal to a width dimension of said second plate-like portion.
 3. A reinforcement assembly for a vehicle floor pan as in claim 2 wherein said extruded section reinforcement piece includes a third plate-like portion disposed adjoining said upper rearward edge of said second plate-like portion and is oriented to lay flat against an adjacent bottom contour of an upwardly raised bulkhead region of said vehicle.
 4. A reinforcement assembly for a vehicle floor pan as in claim 1 wherein said extruded section reinforcement piece includes a third plate-like portion disposed adjoining said upper rearward edge of said second plate-like portion and is oriented to lay flat against an adjacent bottom contour of an upwardly raised bulkhead region of said vehicle.
 5. A reinforced vehicle floor pan comprising in operative combination:a) a sheet metal floor pan; b) a light metal extruded section reinforcement member configured to transversely undergird and be matingly secured to a rearwardly disposed portion of said vehicle floor pan in a region of at least one safety belt anchor point including:i) a first substantially horizontal plate-like portion configured to matingly engage a substantially flat bottom surface portion of said vehicle floor pan, said horizontal plate-like portion having at least one rearward edge; and ii) a second upwardly angled plate-like portion connected along said rearward edge of said first plate-like portion and configured to matingly engage an upwardly raised portion of said floor pan in a region where said floor pan adjoins a rear bulkhead, said second plate-like portion having at least one upper rearward edge, said second plate-like portion includes a channel, C-shaped in cross section, formed along an outward facing wall thereof, said channel having a pair of spaced apart upstanding side walls with laterally inwardly extending ends, said walls and ends defining cage sections for retaining fastening elements of other components for attachment to said floor pan; and c) means for securing said reinforcement member to said floor pan.
 6. A reinforcement assembly for a vehicle floor pan as in claim 5 wherein said means for securing includes an adhesively bonded joint connection. 